The invention relates generally to monitoring the health of an engine and more particularly to a system and method for collecting and storing monitored engine data indicative of the health of an engine.
An engine is typically monitored to assess the performance of the engine in its healthy operative state so that the engine may be controlled in a near optimal manner. An engine is also monitored to detect anomalous conditions indicative of degrading engine health so that malfunctions or faults in the engine may be diagnosed in a timely manner. In general, it is desirable that sufficient data from a monitoring suite of sensors is collected and stored, so that technical personnel can be provided with an insight into the fault or failure and be able to diagnose, post incident, the conditions leading to the particular fault or failure. Beyond the need to have a suite of sensors to monitor the requisite engine parameters at an appropriate rate and be able to adequately reproduce a time series of sensor data measurements for future analysis, it is also necessary to ensure that requisite storage space is available to store the monitored data from the sensors.
Complex mechanical systems such as an aircraft typically employ an onboard data acquisition system for collecting digital flight data. In such systems, a number of sensors distributed throughout the aircraft provide data signals representative of the performance of the aircraft and its engines. This flight data is stored in an attendant, physically robust flight data recorder (commonly referred to as the “black box”), so that in the unlikely event of an in-flight mishap, the flight data recorder can be removed and the stored flight performance data and can be analyzed to determine the cause of the mishap. The stored flight data can also be used proactively in diagnostic maintenance of in-flight anomalies.
Flight data recorders collect a predefined set of data parameters at a fixed sampling rate throughout the entire flight. However, and as will be appreciated by those skilled in the art, many aircraft or engine anomalies require data to be collected at higher sampling rates to understand and diagnose faults. For example, in the case of a new aircraft, it is especially important to ensure that anomalous conditions are noted, monitored, and the monitored data preserved for future analysis. Furthermore, some new aircraft will simply not have enough on-board storage to retain the vast amount of data that is produced at a high rate of sampling. This may be a concern especially for new military high performance aircraft that must economize on weight and space. To add to this, the sampling rate of the data that can be collected is typically limited by the capacity of the recorder's storage medium, the physical constraints of the recorder's storage capacity and the expected duration of the flight.
It would be desirable to develop a method and system for collecting flight data at appropriate sampling rates, while efficiently consuming the available storage capacity before the flight ends. In addition, it would be desirable to develop a technique that preserves data preceding the onset of a fault so that anomalous conditions may be captured and detected from the sampled data.